Tuning microwave losses in superconducting resonators

A Gurevich - Superconductor Science and Technology, 2023 - iopscience.iop.org
The performance of superconducting resonators, particularly cavities for particle
accelerators and micro cavities and thin film resonators for quantum computations and …

Systematic improvements in transmon qubit coherence enabled by niobium surface encapsulation

M Bal, AA Murthy, S Zhu, F Crisa, X You… - npj Quantum …, 2024 - nature.com
We present a transmon qubit fabrication technique that yields systematic improvements in T
1 relaxation times. We encapsulate the surface of niobium and prevent the formation of its …

Topical review of quantum materials and heterostructures studied by polarized neutron reflectometry

GL Causer, L Guasco, O Paull… - physica status solidi …, 2023 - Wiley Online Library
A review of the applications of polarized neutron reflectometry (PNR) for the investigation of
quantum materials is provided. Recent studies of superconductors, strongly correlated …

Probing Oxidation-Driven Amorphized Surfaces in a Ta (110) Film for Superconducting Qubit

J Mun, PV Sushko, E Brass, C Zhou, K Kisslinger… - ACS …, 2023 - ACS Publications
Recent advances in superconducting qubit technology have led to significant progress in
quantum computing, but the challenge of achieving a long coherence time remains. Despite …

Salt‐Assisted Vapor–Liquid–Solid Growth of 1D van der Waals Materials

T Pham, K Reidy, JD Thomsen, B Wang… - Advanced …, 2024 - Wiley Online Library
The method of salt‐assisted vapor–liquid–solid (VLS) growth is introduced to synthesize 1D
nanostructures of trichalcogenide van der Waals (vdW) materials, exemplified by niobium …

Scanning tunneling microscopy and spectroscopy characterization of Nb films for quantum applications

G Berti, CG Torres-Castanedo, DP Goronzy… - Applied Physics …, 2023 - pubs.aip.org
Niobium thin films are key components of superconducting microwave resonators. Interest in
these devices has increased dramatically because of their application in quantum systems …

Structure and Formation Mechanisms in Tantalum and Niobium Oxides in Superconducting Quantum Circuits

JS Oh, R Zaman, AA Murthy, M Bal, F Crisa, S Zhu… - ACS …, 2024 - ACS Publications
Improving the qubit's lifetime (T1) is crucial for fault-tolerant quantum computing. Recent
advancements have shown that replacing niobium (Nb) with tantalum (Ta) as the base metal …

Oxygen vacancies in niobium pentoxide as a source of two-level system losses in superconducting niobium

D Bafia, A Murthy, A Grassellino, A Romanenko - Physical Review Applied, 2024 - APS
We identify a major source of quantum decoherence in three-dimensional superconducting
radio-frequency (SRF) resonators and two-dimensional transmon qubits composed of …

Ultrathin Magnesium‐Based Coating as an Efficient Oxygen Barrier for Superconducting Circuit Materials

C Zhou, J Mun, J Yao, A Anbalagan… - Advanced …, 2024 - Wiley Online Library
Scaling up superconducting quantum circuits based on transmon qubits necessitates
substantial enhancements in qubit coherence time. Over recent years, tantalum (Ta) has …

Quasiparticle Spectroscopy, Transport, and Magnetic Properties of Films Used in Superconducting Qubits

KR Joshi, S Ghimire, MA Tanatar, A Datta, JS Oh… - Physical Review …, 2023 - APS
Niobium thin films on silicon substrate used in the fabrication of superconducting qubits
have been characterized using scanning and transmission electron microscopy, electrical …